/*
 * Copyright 2004-2009 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package susano.presen.controller;

import java.util.Enumeration;

import javax.servlet.http.HttpServletRequest;

/**
 * This class handles the request.
 *
 * @author tanaka.akira.2006
 * @version $Id: RequestHandler.java 220 2009-10-13 08:50:15Z tanaka.akira.2006 $
 *
 */
public class RequestHandler {

	/**
	 * The array suffix.
	 */
	protected static final String ARRAY_SUFFIX = "Array";

	/**
	 * The request.
	 */
	protected HttpServletRequest request;

	/**
	 * Constructor.
	 *
	 * @param request
	 *            the request
	 */
	public RequestHandler(HttpServletRequest request) {
		if (request == null) {
			throw new NullPointerException("The request parameter is null.");
		}
		this.request = request;
	}

	/**
	 * Handles the request.
	 *
	 */
	@SuppressWarnings("unchecked")
	public void handle() {
		for (Enumeration<String> e = request.getParameterNames(); e
				.hasMoreElements();) {
			String name = e.nextElement();
			if (name.endsWith(ARRAY_SUFFIX)) {
				request.setAttribute(name, normalize(request
						.getParameterValues(name)));
			} else {
				request.setAttribute(name,
						normalize(request.getParameter(name)));
			}
		}
	}

	/**
	 * Normalizes the value.
	 *
	 * @param value
	 *            the value
	 * @return the normalized value
	 */
	protected String normalize(String value) {
		if ("".equals(value)) {
			return null;
		}
		return value;
	}

	/**
	 * Normalizes the values.
	 *
	 * @param values
	 *            the values
	 * @return the normalized values
	 */
	protected String[] normalize(String[] values) {
		if (values == null) {
			return new String[0];
		}
		String[] ret = new String[values.length];
		for (int i = 0; i < values.length; i++) {
			ret[i] = normalize(values[i]);
		}
		return ret;
	}
}